1. Field of the Invention
This invention relates to a process for the preparation of a 1-aryl-3,4-dihydro-1H-naphthalene-2-one.
2. Description of the Related Art
Tetralones are compounds which are very important as intermediate products for synthesizing steroids and various medicinal starting materials. Among the tetralones, 1-tetralones are relatively inexpensive and are industrially and easily available. However, 2-tetralones such as 1-aryl-3,4-dihydro-1H-naphthalene-2-one are prepared through complex production processes and are not easily available. One of the problems involved in the production process thereof is that a special reaction catalyst is necessary for obtaining 2-tetralones from the epoxides which are the starting materials and, besides, a high yield is not attained.
The 1-aryl-3,4-dihydro-1H-naphthalene-2-one has heretofore been prepared by a method in which epoxides are refluxed in benzene in the presence of lithium perchlorate (Prior art 1), a method in which epoxides are refluxed in sulfuric acid solution (Prior art 2), and a method in which epoxides are refluxed in benzene at the presence of zinc iodide or epoxides are agitated in ether at the presence of boron trifluoride ether complex (Prior art 3).
Prior art 1: Australian Journal of Chemistry, 34(7), 1467 (1981)
Prior art 2: Journal of the Organic Chemistry, 15, 1197 (1950)
Prior art 3: Tetrahedron Letters, 41, 6029 (2000)